RxPG News : Environment

Artificial nose to detect toxic industrial chemicals

Sun, 13 Sep 2009 13:21:45 PST

( from http://www.rxpgnews.com ) Imagine a polka-dotted postage stamp that can sniff out poisonous gases or deadly toxins simply by changing colors.

As reported in the Sept. 13 issue of the journal Nature Chemistry, Kenneth Suslick and his team at the University of Illinois have developed an artificial nose for the general detection of toxic industrial chemicals (TICs) that is simple, fast and inexpensive – and works by visualizing odors. This sensor array could be useful in detecting high exposures to chemicals that pose serious health risks in the workplace or through accidental exposure.

"Our device is simply a digital multidimensional extension of litmus paper. We have a six by six array of different nanoporous pigments whose colors change depending on their chemical environment," said Suslick, the Schmidt Professor of Chemistry at the U. of I. "The pattern of the color change is a unique molecular fingerprint for any toxic gas and also tells us its concentration. By comparing that pattern to a library of color fingerprints, we can identify and quantify the TICs in a matter of seconds."

To create the sensor array, the researchers print a series of tiny colored dots – each a different pigment – on an inert backing such as paper, plastic or glass. The array is then digitally imaged with an ordinary flatbed scanner or an inexpensive electronic camera before and after exposure to an odor-producing substance. And, unlike other electronic-nose technologies that have been tried in the past, these colorimetric sensors are not affected by changes in relative humidity.

While physicists have radiation badges to protect them in the workplace, chemists and workers who handle chemicals have no good equivalent to monitor their exposure to potentially toxic chemicals.

This project, which was funded by the National Institute of Environmental Health Sciences at the National Institutes of Health, exemplifies the types of sensors that are being developed as part of the NIH Genes, Environment and Health Initiative.

"This research is an essential component of the GEI Exposure Biology Program that NIEHS has the lead on, which is to develop technologies to monitor and better understand how environmental exposures affect disease risk," said NIEHS director Linda Birnbaum. "This paper brings us one step closer to having a small wearable sensor that can detect multiple airborne toxins."

To test the application of their color sensor array, the researchers chose 19 representative examples of toxic industrial chemicals. Chemicals such as ammonia, chlorine, nitric acid and sulfur dioxide at concentrations known to be immediately dangerous to life or health were included.

The laboratory studies used inexpensive flatbed scanners for imaging. The researchers have developed a fully functional prototype handheld device that uses inexpensive white LED illumination and an ordinary camera, which will make the whole process of scanning more sensitive, smaller, faster, and even less expensive. It will be similar to a card-scanning device. The device is now being commercialized by iSense, located in Palo Alto, Calif., and Champaign.

The researchers say older methods relied on sensors whose response originates from weak and highly non-specific chemical interactions, whereas this new technology is based on stronger dye-analyte interactions that are responsive to a diverse set of chemicals. The power of this sensor to identify so many volatile toxins stems from the increased range of interactions that are used to discriminate the response of the array.

"One of the nice things about this technology is that it uses components that are readily available and relatively inexpensive," said David Balshaw, Ph.D. program administrator at NIEHS. "Given the broad range of chemicals that can be detected and the high sensitivity of the array to those compounds, it appears that this device will be particularly useful in occupational settings."

Drinking water DBPs safe for fetal survival

Thu, 07 Sep 2006 00:44:37 PST

( from http://www.rxpgnews.com ) Are disinfection by-products (DBPs) in drinking water harmful to an unborn fetus? According to a study in the November issue of the American Journal of Epidemiology (available online September 5), a team of researchers at the University of North Carolina School of Public Health headed by David A. Savitz, Ph.D., Director of the Center of Excellence in Epidemiology, Biostatistics, and Disease Prevention at MSSM, and formerly Chair of the Department of Epidemiology at the University of North Carolina at Chapel Hill, have determined that drinking water DBPs -- in the range commonly encountered in the US -- do not affect fetal survival. This finding is particularly important because previous research has suggested that exposure to elevated levels of drinking water DBPs might cause pregnancy loss.

The interaction of chlorine with organic material in raw water supplies produces chemical DBPs of health concern, including trihalomethanes (THMs) and haloacetic acids (HAAs). Several epidemiological studies have addressed potential reproductive toxicity of DBPs. The strongest support in ealier studies was noted for pregnancy loss, including stillbirth.

Researchers looked at three locations with varying DBP levels and evaluated 2,409 women in early pregnancy to assess tap water DBP concentrations, water use, other risk factors and pregnancy outcome. Tap water concentrations were measured in the distribution system on a weekly or biweekly basis. DBP concentration and ingested amount, bathing/showering and integrated exposure that included ingestion and bathing/showering were considered. Based on 258 pregnancy losses, the finding did not show an increased risk of pregnancy loss in relation to ingested amounts of DBPs.

"Decisions about treating drinking water nationwide rest in part on these health concerns, and our results provide assurance that there is no measurable adverse effect of disinfection by-products on risk of miscarriage. Given the need to control risk of infection through treatment and the huge expense involved in further reducing DBPs, this is good news for the water utility industry and their customers" said David A. Savitz, Ph.D., lead investigator and Director of the Center of Excellence in Epidemiology, Biostatistics, and Disease Prevention at MSSM.

Household cleaners and air fresheners emit toxic pollutants

Thu, 25 May 2006 12:32:37 PST

( from http://www.rxpgnews.com ) When used indoors under certain conditions, many common household cleaners and air fresheners emit toxic pollutants at levels that may lead to health risks, according to a new study by researchers at the University of California, Berkeley, and Lawrence Berkeley National Laboratory.

Exposure levels to some of the pollutants - and to the secondary pollutants formed when some of the products mix with ozone - may exceed regulatory guidelines when a large surface is cleaned in a small room or when the products are used regularly, resulting in chronic exposure, according to the study.

The study is the first to measure emissions and concentrations of primary and secondary toxic compounds produced by these products under typical indoor use conditions, and it examines the potential hazards of small-scale yet widespread utilization of an array of products designed for household use.

"We've focused a lot of effort in the last decades on controlling the big sources of air pollution and on the chemicals in consumer products that contribute to outdoor ozone formation. However, now we've learned that we need to pay attention to other aspects of pollution sources that are right under our nose," said William Nazaroff, a UC Berkeley professor of environmental engineering and the study's lead author.

To comply with its mandate to protect public health and welfare, for the past four decades the California Air Resources Board (ARB) has been developing and implementing regulatory programs to reduce air pollution in the state. These regulations also cover emissions of volatile organic compounds from consumer products used in homes and institutions.

Several years ago, when a handful of new studies raised the concern that consumer products may be contributing to indoor pollution levels in ways that were not fully understood, the ARB commissioned Nazaroff and his team to study the problem.

Four years in the making, the team's 330-page study and report, "Indoor Air Chemistry: Cleaning Agents, Ozone and Toxic Air Contaminants," was posted online by the ARB on Wednesday, May 10.

The ARB asked Nazaroff and his team to focus their work in two areas: an investigation of toxic air contaminants in household cleaning products and air fresheners, especially a class of chemicals known as ethylene-based glycol ethers; and an examination of the chemistry that occurs when such products are used indoors - in particular, products that contain a reactive group of chemicals called terpenes.

Ethylene-based glycol ethers are common, water-soluble solvents used in a variety of cleaning agents, latex paints and other products. They are classified as hazardous air pollutants under the U.S. Environmental Protection Agency's 1990 Clean Air Act Amendments and as toxic air contaminants by California's Air Resources Board. Their toxicity varies with their chemical structure.

Terpenes are a class of chemicals found in pine, lemon and orange oils that are used in many consumer products either as solvents or to provide a distinctive scent. Although terpenes themselves are not considered toxic, some recent studies have shown that they may react with ozone to produce a number of toxic compounds. (The primary constituent of smog, ozone enters the indoor environment from infiltration of outdoor air, but is also produced indoors by some office machines such as copiers or printers, and by some devices marketed as "air purifiers" that purposely emit ozone into the indoor environment.)

The research team's first task was to determine which household products contain terpenes and glycol ethers, and in what quantities. It compiled a list of the household cleaners and air fresheners available at any of five chain retail outlets in Northern California, then examined the labels and advertising claims (e.g. "pine-scented") for these products and reviewed available product data sheets. Based on this information, they selected the 21 products most likely to contain significant amounts of terpenes and ethylene-based glycol ethers: four air fresheners and 17 cleaning products, including at least one each of disinfectants, general-purpose degreasers, general-purpose cleaners, wood cleaners, furniture maintenance products, spot removers and multi-purpose solvents.

A complete chemical analysis of these 21 products revealed that:

Twelve contained terpenes and other ozone-reactive compounds at levels ranging from 0.2 to 26 percent by mass.

Six contained levels of ethylene-based glycol ethers of 0.8 to 9.6 percent by mass.

Among the four air fresheners studied, three contained substantial quantities of terpenes (9-14 percent by mass)

When the researchers tested the terpene-containing products in the presence of ozone, they found that reactions produced very small particles with properties like those found in smog and haze; other oxidation products; and formaldehyde, a respiratory irritant that is classified as a Group 1 carcinogen. (This designation by the International Agency for Cancer Research is reserved for substances for which there is sufficient evidence to conclude that they cause cancer in humans.) The amounts of terpenes that were converted into these pollutants was dependent on the amount of ozone present.

After completing their chemical analyses, the researchers ran a series of 18 experiments to determine the levels of exposure people might be subjected to when using the products in a confined space. The tests were conducted in a 230-square-foot room with ventilation at an ordinary level which provided approximately one air change every two hours. In some tests of terpene-containing products, ozone was introduced into the room at levels mimicking those that could occur in households or offices.

The products were used in various ways according to package directions: some at full-strength and others at various dilutions as recommended on their labels. In some tests, used cleaning supplies such as paper towels and sponges were left in the room. In others, supplies were promptly removed.

The tests produced various results - some reassuring, and some raising concerns.

The good news, the researchers reported, is that when people use the products under ordinary circumstances, their exposure to ethylene-based glycol ethers, formaldehyde and fine particles will normally not reach guideline values: that is, levels set by regulatory agencies as the maximum exposure levels believed to be safe. However, the authors pointed out, because formaldehyde is also released from other sources such as plywood and pressed wood products that are found in most buildings, any increase in formaldehyde emissions is undesirable.

In several realistic use scenarios, the tests showed that people could be exposed to potentially dangerous levels of toxic pollutants. The scenarios included:

Cleaning in a small, moderately ventilated bathroom. In calculations based on emissions from one of the glycol-ether containing products, the team found that a person who spends 15 minutes cleaning scale off of a shower stall could inhale three times the "acute one-hour exposure limit" for this compound set by the California Office of Environmental Health Hazard Assessment.

Air freshener and ozone in a child's bedroom. This scenario could occur when people use both air fresheners and ozone-generating devices simultaneously in a room. This could lead to exposures to formaldehyde that are 25 percent higher than California's guideline value. Because other sources of formaldehyde could also be present in the room, exposure to formaldehyde would probably be even higher, the report states.

Cleaning when outdoor ozone levels are high. This scenario simulates an apartment in Southern California on a day when the mid-afternoon outdoor ozone concentration is high. A person who stays in the kitchen for two hours after using a moderate amount of one of the terpene-containing products would breathe in about one quarter of the total daily guideline value for particulate matter.

Multi-house cleaning by a professional home cleaner. Under this scenario, a person who cleans four houses a day, five days per week, 50 weeks per year, would take in about 80 micrograms per day of formaldehyde, double the guideline value set by California's Proposition 65. In addition, the person's intake of fine particulate matter during the hours spent cleaning would exceed the average federal guideline level for an entire year. These quantities are in addition to the formaldehyde and particulate matter that the person would be exposed to from all other sources and activities during the year.

The take-home message from these studies, according to Nazaroff, is that everyone - but especially cleaning professionals - should be cautious about overuse of products with high levels of ethylene-based glycol ethers and terpenes. Rooms should be ventilated during and after cleaning, some products should be used in diluted solutions as opposed to full-strength, and cleaning supplies should be promptly removed from occupied spaces once cleaning is done. Also, people should avoid the use of ozone generators or ionizing air cleaners, especially in the same space where terpene-containing cleaning products or air fresheners are being used.

The report is an important milestone that highlights the need to investigate potential health effects of ultrafine particles produced in such reactions, said Bart Croes, chief of the ARB's Research Division.

"Dr. Nazaroff and his team have done a very thorough scientific assessment of the emissions from cleaning products and how they contribute to exposures of the users," Croes said. "Their results indicate that we need to look beyond the directly emitted compounds."

Common pollutants linked to fetal growth retardation

Thu, 17 Nov 2005 16:32:38 PST

( from http://www.rxpgnews.com ) Babies born to women exposed to high ozone levels during pregnancy are at heightened risk for being significantly underweight, according to researchers at the Keck School of Medicine of the University of Southern California.

Women who breathe air heavily polluted with ozone are at particular risk for having babies afflicted with intra uterine growth retardation-which means babies only fall within the 15th percentile of their expected size. The findings were published early online on the Web site of Environmental Health Perspectives, the journal of the National Institute for Environmental Health Sciences (NIEHS).

"These findings add further evidence that our ozone standards are not protecting the most vulnerable members of the population," says Frank D. Gilliland, M.D., Ph.D., professor of preventive medicine at the Keck School and the study's senior author.

Gilliland and his colleagues examined birth records from 3,901 children who were born in California between 1975 and 1987 and participated in the Children's Health Study. Researchers with the USC-led Children's Health Study have monitored levels of major pollutants in a dozen Southern California communities since 1993, while following the respiratory health of more than 6,000 students in those communities.

The researchers gathered data such as the children's gestational age and birth weight, as well as their mothers' zip code of residence at birth. Then they determined levels of ozone, carbon monoxide and other pollutants in the air in each zip code of residence during each mother's pregnancy. Researchers only considered full-term births for the study and controlled for factors such as mothers' smoking habits.

They found that each increase of 12 parts per billion (ppb) of average daily ozone levels over a mother's entire pregnancy was associated with a drop of 47.2 grams (g)-about a tenth of a pound-in a baby's birth weight. And the association was even stronger for ozone exposure over the second and third trimesters, Gilliland says.

In addition, for each 17 ppb increase in average daily ozone levels during a mother's third trimester of pregnancy, the risk of intra uterine growth retardation increased by 20 percent, the scientists report.

The effects were strongest when total average daily ozone exposure rose above 30 ppb. Ozone levels varied from less than 20 ppb in cleaner areas to above 40 ppb in more polluted areas of Southern California.

Carbon monoxide levels affected birth weight as well. They found that each increase of 1.4 parts per million of carbon monoxide concentration during the first trimester was associated with 21.7 g (about .05 pound) decrease in birth weight and a 20 percent increase in risk of intra uterine growth retardation.

Ozone, or O3, is a gas made up of three oxygen atoms. Although a natural layer of ozone in the stratosphere helps protect life on Earth from the sun's rays, ozone at ground level is harmful to health. It is created through interactions among tailpipe exhaust, gasoline vapors, industrial emissions, chemical solvents and natural sources and is worsened by sunlight and heat.

The study findings echo results from the few, smaller studies examining the relationship between ozone and birth weight. Animal studies support the role of O3 in reduced birth weight: in these models, pregnant rats were particularly vulnerable to lung inflammation from O3. Researchers suspect that inflammation from O3 may prompt the release of certain chemicals into the bloodstream, which may harm the placenta.

Carbon monoxide, meanwhile, is an odorless gas that primarily comes from vehicle exhaust. In high concentrations, the gas can harm healthy people; and in lower concentrations, it can hurt those with heart disease and can affect the nervous system.

The gas reduces hemoglobin's ability to carry oxygen where it is needed in the body; that may hurt the delivery of oxygen to a fetus. However, more research is needed to understand the roles of ozone and carbon monoxide in fetal development.

"Fetal growth and birth weight are strongly linked to morbidity and mortality during childhood and adulthood," Gilliland says, "so it's clear that air quality is important to everyone's healthy development."

17 percent of infants living near "stop and go" traffic suffer from wheezing

Sat, 23 Jul 2005 01:03:38 PST

( from http://www.rxpgnews.com ) University of Cincinnati (UC) environmental health researchers have found that 17 percent of infants living near "stop and go" traffic suffer from wheezing.

The study is the first of its kind to analyze the effects of "stop and go" bus and truck diesel traffic versus highway traffic on infant respiratory health.

Published in the August issue of the Journal of Allergy and Clinical Immunology, results of the four-year study suggest that the type of traffic and distance from it-- not just traffic volume--are associated with infant wheezing. Previous air pollution studies had not addressed these factors in infants.

"During the first year of life, an infant's lungs and immune system are still developing," said Patrick Ryan, lead author for the study in UC's Department of Environmental Health. "Overexposure to harmful particulates at such a young age may play a role in the development of allergic conditions."

The researchers tracked the respiratory health of 622 infants living near three traffic conditions: highway traffic, "stop and go" traffic, and areas unexposed to major roads or bus routes. A "stop and go" traffic area was defined as being within 100 meters (about 100 yards) of a bus or state route with a posted speed limit of 50 mph or less.

Research showed that infants living within 100 meters of "stop and go" traffic wheezed twice as often as those living within 400 meters (about 400 yards) of interstates, and more than three times as often as unexposed children.

African American infants living near "stop and go" traffic experienced the highest wheezing rate--25 percent.

"Our study illustrates that living within a football field's distance of 'stop and go' traffic puts infants at a higher risk for wheezing," said Ryan. "Traditional wisdom told us that highway traffic was to blame. We now know that's not necessarily the case."

Earlier research has shown that diesel exhaust particles (DEP), breathable particles able to absorb and transport proteins, aggravate rhinitis (hayfever) and asthma symptoms. According to the Ohio Environmental Council, 23 percent of Cincinnati residents live in areas of elevated DEP exposure, deemed "hot spots."

This year, U.S. Senator George Voinovich (R-OH) introduced the Diesel Emissions Reduction Act, an effort to improve air standards through diesel engine retrofits.

"Our findings reinforce the need to control diesel exhaust emissions," said epidemiologist Grace LeMasters, PhD, professor of environmental health and principal investigator of the study.

Biological mechanism might link particle pollution and heart attack risk

Wed, 08 Jun 2005 20:05:38 PST

( from http://www.rxpgnews.com ) Researchers from the Harvard School of Public Health and colleagues assessed the effect of high air pollution levels, specifically emissions from coal-burning power plants and diesel vehicles, on Boston-area adults with diabetes. Their study found that on days when air pollution levels were high, adults with diabetes were at higher risk for cardiovascular problems due to impairments in blood vessel function.

These results show a biological mechanism linking particulate pollution and impaired cardiovascular function. The findings appear in the June 7, 2005 issue of Circulation: Journal of the American Heart Association.
The study compared the effect of pollution on 270 greater Boston residents divided into two groups; one positively diagnosed with either type I or type II diabetes and the other comprised of non-diabetic individuals but with a family history of diabetes.

To assess blood vessel functioning, an ultrasound device was used to measure how well the participants' arteries were able to expand in response to increased blood flow through the arm.

Impaired blood vessel function is associated with an increased risk for atherosclerosis, heart attacks, stroke, other serious cardiovascular problems and death. On days with either high levels of sulfate particles from power plants or black carbon particles from automobile traffic, the arteries of the diabetics in the study were less able to expand in response to blood flow.

Specifically, on days when sulfate pollution was elevated the researchers found an 11 percent decrease in vascular reactivity among diabetic participants. On days when black carbon concentrations were elevated, diabetic study participants had a 13 percent decrease in vascular reactivity. In comparison, non-diabetics were not affected.

Beginning in the early 1990s researchers at the Harvard School of Public Health showed that particles in the air, predominantly from coal-burning power plants and traffic emissions, were associated with nearly 100,000 cardiovascular related deaths per year. What wasn't clear at that time was a demonstrated mechanism linking particle pollution to an increased risk for heart attacks or death.

Joel Schwartz, senior author of the study and professor of environmental epidemiology at the Harvard School of Public Health said, "This research highlights an important mechanism by which particles can increase the risk of heart attacks and deaths. If particles can impair the function of our arteries, it is understandable that this could increase the risk of death from heart disease. This puts greater emphasis on controlling air pollution sooner rather than later." Schwartz also noted that subjects without diabetes were not affected. "The number of diabetics in the US population is increasing rapidly, suggesting the impact of air pollution is likely to rise. This study shows that both coal-burning powerplants and diesel engines produce dangerous pollutants and should be controlled," said Schwartz. Because everyone did not respond the same, Schwartz highlighted the need for studies to identify other susceptible populations in addition to diabetics.

Study Points to Role of Toxins in Inherited Disease

Fri, 03 Jun 2005 17:21:38 PST

( from http://www.rxpgnews.com ) A disease you are suffering today could be a result of your great-grandmother being exposed to an environmental toxin during pregnancy.

Researchers at Washington State University reached that remarkable conclusion after finding that environmental toxins can alter the activity of an animals genes in a way that is transmitted through at least four generations after the exposure. Their discovery suggests that toxins may play a role in heritable diseases that were previously thought to be caused solely by genetic mutations. It also hints at a role for environmental impacts during evolution.

Its a new way to think about disease, said Michael K. Skinner, director of the Center for Reproductive Biology. We believe this phenomenon will be widespread and be a major factor in understanding how disease develops.

Skinner and a team of WSU researchers exposed pregnant rats to environmental toxins during the period that the sex of their offspring was being determined. The compounds vinclozolin, a fungicide commonly used in vineyards, and methoxychlor, a pesticide that replaced DDT are known as endocrine disruptors, synthetic chemicals that interfere with the normal functioning of reproductive hormones.

Skinners group used higher levels of the toxins than are normally present in the environment, but their study raises concerns about the long-term impacts of such toxins on human and animal health. Further work will be needed to determine whether lower levels have similar effects.

Pregnant rats that were exposed to the endocrine disruptors produced male offspring with low sperm counts and low fertility. Those males were still able to produce offspring, however, and when they were mated with females that had not been exposed to the toxins, their male offspring had the same problems. The effect persisted through all generations tested, with more than 90 percent of the male offspring in each generation affected. While the impact on the first generation was not a surprise, the transgenerational impact was unexpected.

Scientists have long understood that genetic changes persist through generations, usually declining in frequency as the mutated form of a gene gets passed to some but not all of an animals offspring. The current study shows the potential impact of so-called epigenetic changes.

Epigenetic inheritance refers to the transmission from parent to offspring of biological information that is not encoded in the DNA sequence. Instead, the information stems from small chemicals, such as methyl groups, that become attached to the DNA. In epigenetic transmission, the DNA sequences the genes remain the same, but the chemical modifications change the way the genes work. Epigenetic changes have been observed before, but they have not been seen to pass to later generations.

While this research focused on the impact of these changes on male reproduction, the results suggested that environmental influences could have multigenerational impacts on heritable diseases. According to Skinner, epigenetic changes might play a role in diseases such as breast cancer and prostate disease, whose frequency is increasing faster than would be expected if they were the result of genetic mutations alone.

The finding that an environmental toxin can permanently reprogram a heritable trait also may alter our concept of evolutionary biology. Traditional evolutionary theory maintains that the environment is primarily a backdrop on which selection takes place, and that differences between individuals arise from random mutations in the DNA. The work by Skinner and his group raises the possibility that environmental factors may play a much larger role in evolution than has been realized before. This research was supported in part by a grant to Skinner from the U.S. Environmental Protection Agencys STAR Program.

Tollbooth Ventilation System Effective in Protecting Workers from Traffic Air Pollution

Sat, 07 May 2005 15:44:38 PST

( from http://www.rxpgnews.com ) Although there is the potential for tollbooth workers at the Baltimore Harbor Tunnel to be exposed to high levels of cancer-causing air toxins emitted from the thousands of vehicles that pass under their nose, researchers from the Johns Hopkins Bloomberg School of Public Health found that the tollbooth ventilation system was effective in keeping air toxins out of the tollbooth and away from the workers. The researchers measured levels of volatile organic compounds (VOCs) and particle-bound polycyclic aromatic hydrocarbons (PAHs) inside and outside the tollbooth and found relatively high levels outdoors and relatively low levels indoors. The study is published in the May 1, 2005, issue of Environmental Science & Technology.

Tollbooth facilities represent a potential worst-case scenario for occupational exposure to mobile source-related air pollution, as these employees spend a majority of their shift within an arms length of thousands of vehicles emitting a wide range of toxic pollutants. Yet, little has been done to evaluate worker exposure and the protection afforded by the indoor environment, Amir Sapkota, PhD, lead author of the study and a post-doctoral fellow in the Bloomberg School of Public Healths Department of Environmental Health Sciences.

In June 2001, the researchers measured the concentration of air toxins at a tollbooth at the Baltimore Harbor Tunnel. They also examined traffic volume in addition to curbside pollutant concentrations and the concentrations inside the tollbooth. They compared air toxin levels during the three shifts worked by tollbooth employeesmorning (6 a.m.2 p.m.), afternoon (210 p.m.) and night (10 p.m.6 a.m.).

The researchers found that levels of 1,3-butadiene and benzene peaked with the morning and afternoon rush-hour traffic. In contrast, they found that the levels inside the tollbooth were relatively low and constant. They found, however, that some of the chlorinated VOCs used in dry cleaning, air deodorizers and cleaning products were present in higher concentrations inside the tollbooth than outdoors.

It is wonderful to discover that the tollbooth environment is doing what it is designed to doprotect workers from the hazardous environment in which they would otherwise be immersed. It is important to note, however, that not all tollbooth workers in this country, and especially in developing countries, are provided with this protection, said Timothy J. Buckley, PhD, MHS, senior author of the study and an associate professor in the Bloomberg School of Public Healths Department of Environmental Health Sciences.

Genetic diversity predicts susceptibility to a deadly emerging disease

Thu, 14 Apr 2005 15:58:38 PST

( from http://www.rxpgnews.com ) New infectious diseases threaten humans, livestock and the conservation of endangered wildlife. Like nearly a third of all amphibians, the Italian agile frog is a declining species facing potential extinction.

In north western Italy its populations are severely depleted in genetic variation, while eastern populations remain genetically variable. Theory and molecular immunology predict that reduced genetic diversity increases susceptibility to new diseases.

Does reduced genetic diversity over a large portion of a species' range imply similarly widespread disease risk? In the April issue of Ecology Letters, Pearman and Garner report an experimental test of this prediction.

They exposed tadpoles of the Italian agile frog to a virus isolated in North America, thereby simulating the pathogen's outbreak in Europe. The disease susceptibility of tadpoles paralleled the genetic variability in their populations of origin. This result highlights the potential dangers of population bottlenecks and inbreeding, while suggesting a means to predict responses to new infectious diseases.

Efficient Charcoal Production in Africa can save Millions of Lives

Fri, 01 Apr 2005 17:24:38 PST

( from http://www.rxpgnews.com ) A study by researchers at the University of California, Berkeley, and the Harvard School of Public Health, finds that promoting cleaner, more efficient technologies for producing charcoal in Africa can save millions of lives and have significant climate change and development benefits. The findings appear in the April 1, 2005 issue of the journal Science.

image
indoor wood stove
The African continent depends on wood and charcoal for cooking and heating homes. In 2000, nearly 470 million tons of wood were consumed in homes in sub-Saharan Africa in the form of firewood and charcoal, more wood per capita than any other region in the world. More than 1.6 million people, primarily women and children, die prematurely each year worldwide (400,000 in sub-Saharan Africa) from respiratory diseases caused by the pollution from such fires. The study finds that smoke from wood fires used for cooking will cause an estimated10 million premature deaths among women and children by 2030 in Africa and release about 7 billion tons of carbon in the form of greenhouse gases to the environment by 2050, about six percent of the total expected greenhouse gases from the continent.

The authors assessed multiple strategies to reduce mortality as well as greenhouse gas emissions from household fuel sources. They gathered a large database of current fuel use in African nations and defined multiple scenarios for future fuel use by varying the mix of wood, charcoal and petroleum-based fuels used in households and improving the sustainability of wood harvesting and charcoal production techniques.

Robert Bailis, graduate student at the Energy and Resources Group at UC Berkeley and the lead author of the paper said, "If the rapid urbanization continues and all signs indicate that it will then the trend is going to be toward greater charcoal use in Africa. It's the most affordable source of household energy. But whichever path Africa takes, we are saying there are multiple consequences, including preventable deaths and pollution emissions. Decisions made now or in the near future are going to have large effects on health and environmental outcomes in the distant future."

The results of the study show that the best situation in Africa would be to transition from biomass fuels to petroleum-based fossil fuels such as kerosene and liquid propane gas, which can prevent between 1.3 and 3.7 million premature deaths, depending on the speed of transition. They argue, however, that current economic conditions and energy infrastructure in Africa make petroleum-based fossil fuels an unlikely option. "If you switch everyone off the dirtiest fuels to burning clean fossil fuels, you get the biggest health benefit," acknowledged Daniel Kammen, the Class of 1935 Distinguished Chair of Energy at UC Berkeley and a co-author of the paper. He continued, "But the economic cost to most African nations collectively the poorest region of the globe of that switch is impossible."
image
charcoal production - Kenya

Charcoal burns cleaner and produces less indoor pollution than wood, but the current inefficient production method in Africa is one of the most polluting for the global environment and potentially destructive to African forests. Their analysis shows that charcoal can provide comparable health benefits of between 1 and 2.8 million avoided deaths. Majid Ezzati, Assistant Professor of International Health at the Harvard School of Public Health and a co-author of the paper added "It's a lot easier to disseminate charcoal in large scale than fossil fuels, because there is a well developed market and you don't need expensive infrastructure like refineries and processing. So, even though fossil fuels are in fact better for health and better for climate, they are more expensive and a lot harder to get out."

However, scenarios that envision large shifts to charcoal without improvements in harvesting and production lead to severe increases in greenhouse gas emissions, with over 15 billion tons of carbon released into the atmosphere by 2050. "Most charcoal is produced in Africa by one or two guys going out in the woods, almost always without a permit and on somebody else's land, cutting down a tree or two, chopping it up, lighting it, covering it with dirt, and then hovering around it for 2-4 days while it becomes charcoal," Kammen said. "It's no surprise it's not generally a high-efficiency operation." The authors found that by creating the technological and policy tools for transitioning to higher efficiency charcoal production technologies and sustainable harvesting, like those used today in Brazil and Thailand, greenhouse gas emissions can be reduced by 45-66 percent.

The researchers conclude that helping African nations make the transition to clean charcoal without drastically increasing pollution and decimating tropical forests would be an excellent way to achieve several of the United Nation's "millennium development goals," among them reducing child mortality, and ensuring gender equity and environmental sustainability, and to invest in development of the African continent as promised at the 2005 World Economic Forum and the recent G-8 summit. Ezzati said, "This study shows that choosing energy technologies with an eye toward improving health and quality of life in one of the worlds most impoverished areas offers us opportunity to significantly reduce premature deaths, especially among women and children."

Traffic Fumes Boost Oxygen Free Radical Activity and cause DNA Damage

Tue, 22 Mar 2005 20:33:38 PST

( from http://www.rxpgnews.com ) To gauge the levels of exposure to traffic fumes, the research team assessed the amount of a chemical called 1-OHPG in the urine of 47 female motorway toll-booth operators and 27 female office workers.

The 20 toll booths were located on a motorway 10 km south of Taipei, Taiwan, and have the highest traffic density of any toll station in the country.

To test the effects of exposure, they measured 8-OHdG in the urine. This is an indicator of DNA damage caused by oxygen free radical activity in the body.

Blood samples were also taken to measure the levels of circulating nitric oxide, which indicates harmful oxidation associated with traffic fumes.

The operators worked in eight hour shifts, for four consecutive days, before taking a day off. During their shift, they took breaks of between 30 and 45 minutes every couple of hours. They regularly changed lane booth, working a rotation system.

Smoking also increases the amount of urinary 8-OHdG, and there were more smokers among the office workers.

But levels of urinary 8-OHdG were an average of 90% higher among the non-smoking toll booth operators than they were among the office workers. Levels of nitric oxide were an average of 30% higher.

The levels of 1-OHPG were strongly linked to the levels of 8-OHdG. The higher the 1-OHPG, the higher was the 8-OHdG. And this held true even after adjusting for smoking or mode of transport to work.

The authors conclude that traffic fumes boost oxygen free radical activity and therefore DNA damage, and that environmental levels should be curbed to protect people's health.

Why African American children suffer disproportionately from tobacco-related illness

Fri, 04 Mar 2005 21:02:38 PST

( from http://www.rxpgnews.com ) A new study may help explain why African American children suffer disproportionately from tobacco-related illness.

The Cincinnati Children's Hospital Medical Center study shows that African American children with asthma have significantly higher levels of cotinine -- a substance produced when the body breaks down nicotine -- even though these children's parents report lower exposure to environmental tobacco smoke, commonly known as second-hand smoke.

"There are at least two possible reasons why African Americans have higher levels of cotinine," says Stephen E. Wilson, MD, a scientist at the Cincinnati Children's Center for Environmental Health and the study's lead author. "Numerous studies have demonstrated significant racial differences in the metabolism of tobacco-related products. But differences in additives to cigarettes commonly smoked by African Americans, such as menthol, could also explain the observed racial differences."

The study will be published in the March issue of Environmental Health Perspectives and is currently available online at http://ehp.niehs.nih.gov/

The study is based on data from the Cincinnati Asthma Prevention study, an ongoing study of the Cincinnati Children's Center for Environmental Health. Dr. Wilson and his colleagues measured cotinine in the blood and hair of 222 children with asthma. Cotinine is considered the best marker of environmental tobacco smoke exposure. The investigators also assessed exposure to environmental tobacco smoke using a validated survey.

Surprisingly, the investigators found that African American children with asthma had higher levels of cotinine in the blood (1.41 ng/ml vs. 0.97 ng/ml) and hair (0.25 ng/mg vs. 0.07 ng/mg) compared to white children. This pattern held true even after taking into account tobacco smoke exposure, size of home and other sociodemographic characteristics, according to Dr. Wilson.

"These differences in cotinine could provide clues to the racial differences in tobacco-associate morbidity and mortality," says Dr. Wilson. "If African American children are more susceptible to tobacco-induced toxicity, we should target policy initiatives to reduce exposure among this population."

Perchlorate found in US breast milk samples

Wed, 23 Feb 2005 19:41:38 PST

( from http://www.rxpgnews.com ) In a new study of breast milk and store-bought milk from across the United States, scientists at Texas Tech University found perchlorate in every sample but one. The results suggest that this thyroid-disrupting chemical may be more widespread than previously believed.

Perchlorate occurs naturally and is also a primary ingredient in solid rocket fuel. The chemical, which has been showing up in many segments of the environment, can interfere with iodide uptake in the thyroid gland, disrupting adult metabolism and childhood development.

The researchers, led by Professor Purnendu Dasgupta, Ph.D., of the university's department of chemistry and biochemistry, analyzed 47 dairy milk samples purchased randomly from grocery stores in 11 states, and 36 breast milk samples from women recruited at random in 18 states. Every sample of breast milk contained perchlorate, and only one sample of dairy milk contained no detectable levels.

The average perchlorate concentration in breast milk was 10.5 micrograms per liter; the dairy milk average was 2.0 micrograms per liter. No definitive national standard exists, although the U.S. Environmental Protection Agency had suggested a limit of 1.0 micrograms per liter in drinking water.

The researchers also found that high levels of perchlorate correlated with low levels of iodide in breast milk, which can inhibit thyroid function in nursing womenan essential component for proper neural development of the fetus. Although the data are limited, the levels of iodide in this study are sufficiently low to be of concern, according to the researchers. They suggest that the recommended daily intake of iodine for pregnant and nursing women may need to be revised upwards.

Air pollution thickens the blood and boosts inflammation

Mon, 21 Feb 2005 16:18:38 PST

( from http://www.rxpgnews.com ) A new study may help to explain why air pollution is associated with an increased risk of heart attacks, stroke, and worsening respiratory problems. Air pollution, and especially particulate matter, thickens the blood and boosts inflammation, finds experimental research in Occupational and Environmental Medicine.

The research team tested the inflammatory and blood clotting responses of human immune cell (macrophages) and umbilical cord and lung cells, six and 24 hours after exposure to particulate matter.

The results showed that clotting factors, which thicken the blood, were enhanced in almost all the cell types. The rate of death in immune cells also significantly increased, and exposure to the pollutants boosted inflammatory activity.

The authors say their findings suggest that particulate matter has the ability to alter cell function so that it promotes thickening or coagulation of the blood. And they point to a potential synergy between the factors that boost inflammation and blood thickening.

Ultrafine particles of inhaled particulate matter can enter the bloodstream, raising the possibility that their "thickening" effects on macrophages might have an impact on the plaques found on artery walls. Macrophages are a major component of arterial plaques.

"Averages don't kill people - it is the extremes"

Sun, 20 Feb 2005 19:40:38 PST

( from http://www.rxpgnews.com ) As a result, governments and health officials need to begin to think about how to respond to an anticipated increase in the number and scope of climate-related health crises, ranging from killer heat waves and famine, to floods and waves of infectious diseases.

That, in a nutshell, was the message delivered to scientists here today (Feb. 20) at the annual meeting of the American Association for the Advancement of Science (AAAS) by Jonathan A. Patz, an authority on the human health effects of global environmental change.

As the world's climate warms, and as people make widespread alterations to the global landscape, human populations will become far more vulnerable to heat-related mortality, air pollution-related illnesses, infectious diseases and malnutrition, Patz says.

"We are destined to have some warming," says Patz, a professor of environmental studies and population health studies at the University of Wisconsin-Madison.

But it won't be a gradually warming world that triggers future health crises, says Patz, a scientist based at the UW-Madison Center for Sustainability and the Global

Environment. It will be a dramatic increase in severe weather events - major storms, heat waves, flooding - triggered by a shifting global climate that will wreak most of the human health havoc.

"Averages don't kill people - it is the extremes," Patz explains.

The issue, Patz says, is how are we going to adapt? If we don't do something to mitigate the potential human health effects of climate change, the world, beginning at the local and regional level, will begin to experience climate-related catastrophe.

"In the face of climate change, what are the adaptive measures at many and variable scales that we can take to reduce the health impact of climate change? That's what we need to be thinking about," he says.

The Wisconsin scientist suggests we may already be seeing the health consequences of a warmer world: The heat wave that struck Europe in the summer of 2004 claimed an estimated 22,000-35,000 lives, mostly the infirm, elderly and poor.

"That event was so far out of the normal climate range that one analysis pegs it as a signal of climate change," Patz explains. "So what are we going to be adapting to? It won't be creeping temperatures. What we may see is an increased frequency of these extreme events."

Moreover, as temperature regimes change, weather patterns will be altered and increased rainfall will facilitate the spread of waterborne and food-borne disease. And increased local rainfall also will make life easier for the insects and animals that carry some human diseases.

One strategy to mitigate future climate-related health problems, according to Patz, would be to develop and use climate forecasts and warning systems to avert disease and adverse health outcomes.

Such tools are already coming into play. Strong El Nino events, for example, tend to trigger heavier rainfall in the American southwest, setting the stage for rodent population booms and increased risk of exposure to hanta virus, a sometimes deadly disease transmitted through rodent urine and droppings.

Such events can be predicted with confidence, and if higher risk is forecast, people can prepare by mouse-proofing their homes and taking other measures to minimize contact with the source of a serious disease.

"The key will be early detection, warning and responding to threats," Patz says.

In urban areas, steps are already being taken to mitigate the effects of warmer climate and the "heat island" effect created by cities. Rooftop gardens are being encouraged by, among others, the U.S. Environmental Protection Agency, and creating more reflective surfaces by painting rooftops white and using reflective materials in paving projects may reduce overall warming.

It will be important, says Patz, to avoid maladaptation. Increased use of air conditioners, for example, will provide immediate relief and is an important protection during an acute heat event. But the fossil fuels burned to generate the electricity to drive those air conditioners, as well as over-dependence on electric power grid functioning could potentially exacerbate the problem.

"Short-sighted fixes must be avoided," Patz says.

Improving deficiencies in such things as watershed protection, infrastructure and drainage systems would ease the risk of water contamination events. At present in the United States, a developed nation where most people have access to treated water, as many as 9 million cases of waterborne disease are estimated to occur each year.

With climate change, those numbers are likely to go up, says Patz, unless significant steps are taken to minimize the likelihood of sewage overflows and other weather related events that contaminate water supplies.

Air pollutants linked to genetic damage in unborn babies

Wed, 16 Feb 2005 15:41:38 PST

( from http://www.rxpgnews.com ) The air pollutants considered in this study include emissions from cars, trucks, bus engines, residential heating, power generation and tobacco smoking. These pollutants can cross the placenta and reach the fetus.

The study was funded by the National Institute of Environmental Health Sciences, part of the National Institutes of Health, the U.S. Environmental Protection Agency, and other private foundations. The research was conducted by scientists from the Columbia University Center for Children's Environmental Health. Study results will be published in the February issue of Cancer Epidemiology Biomarkers and Prevention, and are available online at http://cebp.aacrjournals.org.

"This is the first study to show that environmental exposures to specific combustion pollutants during pregnancy can result in chromosomal abnormalities in fetal tissues," said Kenneth Olden, Ph.D., the director of NIEHS. "These findings may lead to new approaches for the prevention of certain cancers."

Researchers monitored exposure to airborne pollutants, known as polycyclic aromatic hydrocarbons (PAHs), among non-smoking African-American and Dominican mothers residing in three low-income neighborhoods of New York City -- Harlem, Washington Heights and the South Bronx.

"Although the study was conducted in Manhattan neighborhoods, exhaust pollutants are prevalent in all urban areas, and therefore the study results are relevant to populations in other urban areas," said Dr. Frederica P. Perera, director of the Columbia Center for Children's Environmental Health and senior author of the study.

Exposure to combustion pollutants was assessed through personal questionnaires and portable air monitors worn by the mothers during the third trimester of their pregnancies. Researchers then calculated the concentration of air pollution to which each pregnant woman and her baby were exposed. Study participants exposed to air pollution levels below the average were designated as having "low exposure," while those exposed to pollution levels above the average were designated as having "high exposure."

"We observed 4.7 chromosome abnormalities per thousand white blood cells in newborns from mothers in the low exposure group, and 7.2 abnormalities per thousand white blood cells in newborns from the high exposure mothers," said Perera. "In particular, stable alterations were increased, which are of greatest concern for potential risk of cancer, since cells with this type of abnormality can persist in the body for long periods of time."

Chromosomal abnormalities were measured in umbilical cord blood by a "chromosome painting" technique called fluorescence in situ hybridization, one that enabled researchers to observe the structural changes within the chromosome. Chromosomes are the threadlike packages in the nucleus of the cell that contain the cell's genetic information.

"This evidence that air pollutants can alter chromosomes in utero is troubling since other studies have validated this type of genetic alteration as a biomarker of cancer risk," said Perera. "While we can't estimate the precise increase in cancer risk, these findings underscore the need for policymakers at the federal, state, and local levels to take appropriate steps to protect children from these avoidable exposures."

Previous studies conducted by Perera and colleagues showed that combustion-related air pollutants significantly reduce fetal growth, which may affect cognitive development during childhood.

The study is part of a broader, multi-year research project, "The Mothers & Children Study in New York City," started in 1998, which examines the health effects of exposure of pregnant women and babies to air pollutants from vehicle exhaust, the commercial burning of fuels, and tobacco smoking, as well as from residential use of pesticides and allergens.

Effects of environmental tobacco smoke on children's health

Tue, 04 Jan 2005 18:48:38 PST

( from http://www.rxpgnews.com ) A new Cincinnati Children's Hospital Medical Center study shows that exposure to environmental tobacco smoke, even at extremely low levels, is associated with decreases in certain cognitive skills, including reading, math, and logic and reasoning, in children and adolescents.

The study is the largest ever to look at the effects of environmental tobacco smoke on children's health. It is published in the January issue of Environmental Health Perspectives.

"This study provides further incentive for states to set public health standards to protect children from exposure to environmental tobacco smoke," says Kimberly Yolton, PhD, a researcher at the Children's Environmental Health Center at Cincinnati Children's and the study's main author. "We estimate that more than 33 million children in the United States are exposed to levels consistent with the adverse effects seen in this study."

The study's findings translate into nearly a three-point decline in a standardized reading test and nearly a two-point decline in a standardized math test, given an average score of 100 and a modest increase in exposure to environmental tobacco smoke.

Logic and reasoning skills were tested in a task that involved the assembly of blocks. This task evaluated a child's ability to visually organize and reason in constructing a design quickly and accurately. The study found a .55 decline in block-design scores, given an average score of 10 and a modest increase in exposure.

"These declines may not be clinically meaningful for an individual child, but they have huge implications for our society because millions of children are exposed to environmental tobacco smoke in the United States," says Dr. Yolton.

The study is based on data gathered from 1988-94 for the third National Health and Nutrition Examination Survey (NHANES-III), conducted by the National Center for Health Statistics at the Centers for Disease Control and Prevention. NHANES is designed to collect information about the health and diet of people in the United States.

To measure exposure to environmental tobacco smoke, researchers measured levels of cotinine, a substance produced when nicotine is broken down by the body. Cotinine can be measured in blood, urine, saliva and hair. It is considered the best marker of environmental tobacco smoke exposure.

For this study, cotinine was measured in the blood of 4,399 children between 6 and 16 years old. Children were only included in the analysis if their serum (blood) cotinine levels were at or below 15 ng/ml, a level consistent with environmental tobacco smoke exposure, and if they denied using any tobacco products in the previous five days.

Cognitive and academic abilities were assessed using portions of standardized intelligence and achievement tests. Reading, math and reasoning scores were highly related to environmental tobacco smoke exposure: The greater the levels of exposure as measured by cotinine levels, the greater the decline in reading and reasoning ability, even at extremely low levels of exposure, according to Dr. Yolton.

Surprisingly, Dr. Yolton and colleagues at Cincinnati Children's also found greater decreases in cognitive skills at lower levels of exposure. While there was, on average, a one-point decline in reading scores for each unit increase in cotinine at levels above 1 ng/ml, there was a five-point decline for each unit increase in cotinine at levels below 1 ng/ml. In the United States, 43 percent of children are exposed to environmental tobacco smoke in their own homes, and 85 percent of children have detectable levels of cotinine in their blood.